In automotive distribution systems for conditioned air, such as air that has passed through the HVAC unit of an air conditioning and distribution system, many different architectures have been tried. Some system architectures are laid out such that it is difficult or impossible to achieve desired level of rear and front, and/or bi-level and/or mix mode distributions, or mixed stratifications with the fixed geometry or architecture of the unit. Bi-level modes usually profoundly affect panel and floor distribution; mix modes affect defrost and floor distribution. Particularly as it relates to distribution systems having components, components such as the rear panel or panels often share a feed duct with or within the rear floor. These systems, while providing air to the rear areas of the automotive vehicle, inherently cause the rear and front floor temperatures to track one another or to essentially follow the same heat distribution. Therefore, for example, if a cooler panel mode in the rear is necessary, the HVAC is set up so that hot air is fed to track the air flowing through the floor. In other words, the current system architectures cannot accommodate both requirements of cooler panel mode and hot air tracking at the same time, or other similar modes.
Attempts to provide for an increased or unaffected temperature solution to rear conditioned air delivery using a prior art system architecture, yield panel or defrost mode risk of degradation (or inappropriate reduction or addition of heat) to yield inappropriate or undesirable temperature effects in the front of the vehicle due to changes in the temperature of conditioned air provided to the rear of the vehicle. The present invention, in addition to allowing for increased or non-effected temperatures to the rear of the vehicle, does so without degrading or otherwise inappropriately reducing or adding heat or yielding inappropriate or undesirable temperature effects in the front of the vehicle. In addition, in preferred embodiments of the present invention, not only does the present invention prevent degradation, particularly in panel or defrost modes, it does so without the addition of extra doors or levers or cams.